Chapter 18: Taxonomy Taxonomy: the discipline where scientists classify organisms and assign universally accepted names to each organism.
Aristotle- 384-322 B.C. A. Devised “classical” system that lasted 2,000 years. “Scala naturae”= “great chain of being” plants man A. Aristotle’s system had 2 Kingdoms. 1. Plant Kingdom (trees, shrubs, herbs) 2. Animal Kingdom (land, sea, air)
II. Carolus Linnaeus- botanist who lived in 18th Century II. Carolus Linnaeus- botanist who lived in 18th Century. Developed binomial nomenclature system of naming; 7 category system of classification. A. Problems with common names 1. Misnomers Ex. Jellyfish, silverfish, starfish, goldfish, crayfish 2. Variation in names among languages and regions (localities) Ex. Cougar, puma, mountain lion
Jellyfish Silverfish Only true fish… Goldfish! Starfish Crayfish
Developed scientific names 1. Chose Latin: 18th Century scientists understood Latin. 2. Binomial nomenclature: Two-word naming system. 1st part: genus, 2nd part: species A. Names based on 1. Physical characteristics Ex. Melanoleuca 2. Behavior Ex. Noctivagens 3. Honorary (for people- discoverer, someone of past significance ) 4. Location and Habitat Ex. Californica
You must know the full classification for a human! Categories of classification 1. Kingdom Phylum (Division) Class Order Family Genus Species Animal Chordate Mammal Primate Hominid Homo sapiens You must know the full classification for a human! Animal-Chordate-Mammal-Primate-Hominid-Homo-sapiens
Genus species name is written in italics or underlined Genus species name is written in italics or underlined. Genus is capitalized, species is not. Ex: Homo sapiens or Trifolium agarium
Modern Taxonomy A. Classification is based on similarities 1. Structures (morphology) 2. Biochemical and genetics 3. Evolutionary relationships (phylogeny) 4. Embryology 5. Reproductive potential a. species= organisms that are “reproductively isolated and produce fertile offspring.” *not man-made
Six Kingdom System A. Plants: multicellular, eukaryotic (true nucleus), stationary autotrophs B. Animals: multicellular, mobile, eukaryotic heterotrophs C. Fungi: stationary heterotrophs, eukaryotes D. Protists: unicellular eukaryotes Monera: unicellular prokaryotes E. Archaebacteria– used to be called Monera F. Eubacteria– used to be called Monera